Air chuck

ABSTRACT

An air chuck includes: a finger support part including a pair of fingers and a pair of lock shafts; a chuck main body part including an operation mechanism operable to open and close the fingers; and linking mechanisms that detachably link the finger support part to the chuck main body part. Each of the linking mechanisms causes the corresponding lock shaft to shift to a non-lock position so as to render the pair of fingers capable of being opened and closed when the finger support part is linked to the chuck main body part. Each of the linking mechanisms causes the corresponding lock shaft to shift to a lock position and locks the pair of fingers so as to render the pair of fingers incapable of being opened and closed when the finger support part is detached from the chuck main body part.

TECHNICAL FIELD

The present invention relates to an air chuck including a pair of fingers that is openable and closable and, in particular, to an air chuck configured in such a manner that a finger support part including the pair of fingers is attachable to and detachable from a chuck main body part operable to open and close the pair of fingers.

BACKGROUND ART

Such an air chuck configured in such a manner that a finger support part including an openable and closable pair of fingers is attachable to and detachable from a chuck main body part including an operation mechanism operable to open and close the pair of fingers is well-known as disclosed in, for example, PTL 1 to 3. The finger support part can be replaced in accordance with what kind of workpiece to be handled. The air chuck can thus be used for various kinds of workpieces, and this type of air chuck excels in efficiency and economy accordingly.

Unfortunately, the pair of fingers of the well-known air chuck becomes free when the finger support part is removed from the chuck main body. The pair of fingers shifts freely and is unable to keep a certain positional relationship. Thus, attaching the finger support part to the chuck main body part requires an effort to provide precise alignment between the pair of fingers and the operation mechanism (e.g., a piston) incorporated in the chuck main body part. For automatic replacement of the finger support part through the use of a robot or the like in particular, it is necessary to provide mechanisms such as a mechanism for bringing the pair of fingers into alignment with the operation mechanism and a mechanism for keeping them in alignment.

CITATION LIST Patent Literature

-   PTL 1: Japanese Unexamined Patent Application Publication No.     4-41190 -   PTL 2: Japanese Unexamined Patent Application Publication No.     4-289090 -   PTL 3: Japanese Unexamined Patent Application Publication No.     7-290392

SUMMARY OF INVENTION Technical Problem

The present invention addresses the technical problem of providing an air chuck configured in such a manner that a finger support part including a pair of fingers is attachable to and detachable from a chuck main body part including an operation mechanism operable to open and close the pair of fingers, with the pair of fingers being kept from shifting freely at the time of removal of the finger support part from the chuck main body part and thus being capable of maintaining a certain positional relationship all the time.

Solution to Problem

To solve the aforementioned problem, an air chuck according to the present invention includes: a finger support part including a pair of fingers that is openable and closable; a chuck main body part including an operation mechanism operable to open and close the pair of fingers; and linking mechanisms that detachably link the finger support part to the chuck main body part.

The finger support part includes a pair of lock shafts that shifts between a lock position and a non-lock position. The pair of lock shafts shifts to the non-lock position so as to render the pair of fingers capable of being opened and closed when the finger support part is linked to the chuck main body part. The pair of lock shafts shifts to the lock position and locks the pair of fingers so as to render the pair of fingers incapable of being opened and closed when the finger support part is detached from the chuck main body part.

Each lock shaft of the pair of lock shafts is provided with a corresponding one of the two respective linking mechanisms. When the finger support part is linked to the chuck main body part, each of the linking mechanisms causes the corresponding lock shaft to shift from the lock position to the non-lock position and links the finger support part to the chuck main body part via the lock shaft.

According to the present invention, the pair of lock shafts is preferably capable of shifting between the lock position where the pair of lock shafts is caught in the pair of fingers and the non-lock position where the pair of lock shafts is not caught in the pair of fingers, and each lock shaft is preferably subjected to energizing force exerted by a lock spring toward the lock position. The linking mechanisms each preferably include: a shaft insertion hole formed in a body of the chuck main body part for insertion of the lock shaft; and a shaft catch mechanism that causes the lock shaft to shift to the non-lock position and catches the lock shaft in the chuck main body when the lock shaft is inserted into the shaft insertion hole.

The shaft catch mechanism preferably includes: a catch surface formed on the lock shaft; at least one catch body received in a catch-body reception hole formed in a hole wall of the shaft insertion hole in a manner so as to be capable of shifting between a catch position where the catch body is caught on the catch surface of the lock shaft and a non-catch position where the catch body is off the catch surface; a press member capable of shifting between a press position where the press member presses the catch body toward the catch position and a non-press position where the press member does not press the catch body; and a press spring that exerts energizing force on the press member toward the press position. The catch surface of the lock shaft is preferably a sloping surface that slopes at an angle from an axis of the lock shaft, and the catch surface preferably causes the lock shaft to shift to the non-lock position when the catch body becomes caught on the catch surface.

The following configuration is more preferred. The catch body is a sphere, and the press member is cylindrical and is disposed around the shaft insertion hole and the catch body in a manner so as to be capable of advancing and retreating in a direction of an axis of the shaft insertion hole. A taper surface is formed as an inner surface of the press member. The taper surface presses the catch body toward the catch position when the press member shifts to the press position, and the taper surface releases the catch body from pressing force when the press member retreats to the non-press position.

According to the present invention, the linking mechanisms each preferably include a delinking mechanism that delinks the finger support part from the chuck main body part.

In this case, the delinking mechanism may include a release piston driven by air, and the release piston may cause the press member to shift to the non-press position when the finger support part is delinked from the chuck main body part.

Alternatively, the delinking mechanism may include a manual operation member, and the manual operation member may cause the press member to shift to the non-press position when the finger support part is delinked from the chuck main body part.

According to the present invention, the linking mechanisms each preferably include a catch-body hold mechanism that holds, in the non-catch position, the catch body caused to shift to the non-catch position when the finger support part is detached from the chuck main body part.

In this case, the catch-body hold mechanism includes a hold rod that slots into the shaft insertion hole in a manner so as to be capable of shifting therein. As the finger support part is detached from the chuck main body part, the lock shaft is pulled out of the shaft insertion hole, and at the same time, the hold rod under action of compressed air or under action of a hold spring shifts within the shaft insertion hole and comes into contact with the catch body in the non-catch position so as to hold the catch body in the non-catch position.

Advantageous Effects of Invention

According to the present invention, the pair of fingers is kept locked in a certain position by the lock shafts when the finger support part is detached from the chuck main body part. This facilitates attachment, detachment, and replacement of the finger support part. When the finger support part is automatically replaced through the use of a robot or the like in particular, it is not necessary to bring the pair of fingers into alignment with the operation mechanism. This eliminates the need for mechanisms such as a mechanism for fringing the fingers into alignment and a mechanism for keeping the fingers in alignment.

The finger support part is linked to the chuck main body part via the lock shafts; that is, the lock shafts are capable of locking the pair of fingers and are also capable of linking the finger support part to the chuck main body part. The structure of the linking mechanisms that link the finger support part to the chuck main body part may thus be highly rational.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an oblique frontal perspective view of a first embodiment of an air chuck according to the present invention, illustrating a state in which a finger support part is linked to a chuck main body part.

FIG. 2 is an oblique back perspective view of the air chuck in FIG. 1.

FIG. 3 is a perspective view of the air chuck, illustrating a state in which the finger support part is detached from the chuck main body part.

FIG. 4 is a longitudinal sectional view of the air chuck in FIG. 1.

FIG. 5 is a partial enlargement of FIG. 4.

FIG. 6 is a longitudinal sectional view of the air chuck, illustrating a state in which a pair of fingers is closed.

FIG. 7 is a sectional view of the air chuck in the process of detaching the finger support part from the chuck main body part.

FIG. 8 is a longitudinal sectional view of a second embodiment of the air chuck according to the present invention, illustrating a state in which the finger support part is linked to the chuck main body part.

FIG. 9 is an enlarged view of main part, illustrating a state in which a manual operation member of the air chuck in the second embodiment is rotated to an operation position.

FIG. 10 is a longitudinal sectional view of the air chuck in the second embodiment in the process of detaching the finger support part from the chuck main body part.

FIG. 11 is a longitudinal sectional view of a third embodiment of the air chuck according to the present invention.

FIG. 12 is a longitudinal sectional view of the air chuck in the third embodiment, illustrating a state in which the finger support part is detached from the chuck main body part.

DESCRIPTION OF EMBODIMENTS

FIGS. 1 to 7 illustrate a first embodiment of an air chuck according to the present invention. An air chuck 1A includes; a finger support part 2 including a pair of fingers 5 that is openable and closable; and a chuck main body part 3 incorporating an operation mechanism 6 operable to open and close the pair of fingers 5. The finger support part 2 is detachably linked to the chuck main body part 3 by linking mechanisms 4.

The words “up”, “down”, “front”, “back”, “left”, and “right” hereinafter refer to the respective directions in FIG. 1.

The finger support part 2 includes a support rail 10 having a channel section. The support rail 10 is narrow and is long in right-and-left directions. The pair of fingers 5 is supported in a guide groove 11 on an upper surface of the support rail 10 in a manner so as to be openable and closable along the support rail 10.

The fingers 5 are substantially T-shaped when viewed from the front. The fingers 5 each include a base portion 5 a in the form of a rectangular block and a pinch portion 5 b in the form of a rectangular block extending upward from the base portion 5 a. The base portion 5 a is slidably supported in the guide groove 11 of the support rail 10. Chuck attachments (not illustrated) are attached to the respective pinch portions 5 b, and a workpiece can be pinched between the attachments.

The support rail 10 is provided with two finger lock mechanisms 12. When the finger support part 2 is detached from the chuck main body part 3, the finger lock mechanisms 12 lock the pair of fingers 5 so as to render the pair of fingers 5 incapable of being opened and closed. As can be seen from FIGS. 4 and 5, the two finger lock mechanisms 12 are of the same configuration and each include a lock shaft 13 provided for the corresponding one of the fingers 5. One of the lock shafts 13 is close to one end of the support rail 10 in the longitudinal direction and the other lock shaft 13 is close to the other end of the support rail 10 so that the lock shafts 13 correspond to the individual fingers 5 when the pair of fingers 5 is in the fully open position illustrated in FIG. 4. It can thus be said that the support rail 10 is provided with a pair of lock shafts 13 corresponding to the pair of fingers 5.

The lock shafts 13 each include a trunk portion 13 a in the form of a cylindrical column and a head portion 13 b formed on an upper end (proximal end) of the trunk portion 13 a and having a discoid shape. The diameter of the head portion 13 b is greater than the diameter of the trunk portion 13 a. With the head portion 13 b being fitted in a circular recess 10 a formed on the upper surface of the support rail 10, the lock shaft 13 is movable in up-and-down directions through the support rail 10 and a guide member 14 fixed to a lower surface of the support rail 10 and extends toward a place below the support rail 10.

The guide member 14 is in the form of a circular receptacle and functions as a guide for the lock shaft 13 moving in up-and-down directions and as a spring washer. A lock spring 15 is interposed between the guide member 14 and the head portion 13 b of the lock shaft 13 in a manner so as to be in a compressive state. The lock spring 15 exerts energizing force on the lock shaft 13 all the time in the upward direction in the drawing, that is, in the direction in which an upper surface of the head portion 13 b is pressed against a lower surface of the base portion 5 a of the finger 5.

A lock projection 16 is formed in the center of the upper surface of the head portion 13 b. A lock recess 17 in which the lock projection 16 can be caught is formed on the lower surface of the base portion 5 a of the finger 5. In the example illustrated in the drawings, the lock projection 16 is in the form of a truncated cone and the lock recess 17 is in the form of a conical cavity. Alternatively, the lock projection 16 and the lock recess 17 may have other shapes.

A catch recess 18 having an annular shape is formed in a lower end portion (tip portion) of the lock shaft 13. When the finger support part 2 is linked to the chuck main body part 3 by the linking mechanisms 4, catch bodies 19 of each linking mechanism 4 become caught on a catch surface 18 a of the catch recess 18, as will be described later in detail, in such a manner that the lock shaft 13 compresses the lock spring 15 and shifts in the downward direction in the drawing, that is, in the direction in which the lock projection 16 on the head portion 13 b moves away from the lock recess 17 of the finger 5.

The catch surface 18 a is a sloping surface that slopes toward a tip (lower end) of the lock shaft 13 in a manner so as to gradually increase its distance from a central axis of the lock shaft 13 and is a circular conical surface in the example illustrated in the drawings.

Each of the finger lock mechanisms 12 configured as described above enables the following: when the finger support part 2 is linked to the chuck main body part 3 as illustrated in FIGS. 4 and 5, the catch bodies 19 of the linking mechanism 4 become caught on the catch surface 18 a of the lock shaft 13 such that the lock shaft 13 shifts to a position (non-lock position) where the lock projection 16 of the head portion 13 b is placed away from the lock recess 17 of the finger 5, and consequently, the pair of fingers 5 is rendered capable of being opened and closed. In this state, the support rail 10 of the finger support part 2 is in contact with an upper end of the chuck main body part 3.

When the finger support part 2 is detached from the chuck main body part 3 as illustrated in FIGS. 3 and 7, the lock shaft 13 is pushed by the lock spring 15 and shifts to a position (lock position) where the lock projection 16 is caught in the lock recess 17, and consequently, the pair of fingers 5 is locked; that is, the pair of fingers 5 is rendered incapable of being opened and closed.

The chuck main body part 3 includes a body 23 that is a rectangular parallelepiped. The operation mechanism 6 operable to open and close the pair of fingers 5 is provided in a midsection of the body 23 in the right-and-left directions. As illustrated in FIGS. 4 and 5, the operation mechanism 6 includes a cylinder device 24 and two open-close levers 25 that transmit actions of the cylinder device 24 to the pair of fingers 5.

The cylinder device 24 has a cylinder cavity 26 having a circular shape and extending through the midsection of the body 23 in up-and-down directions along a first axis L1. A lower stopper 27 in the form of a short cylindrical column is attached to a lower end portion of the cylinder cavity 26 so as to form an airtight seal with a sealing member 27 a therebetween, and an upper stopper 28 in the form of a short cylindrical column is attached to an upper end portion of the cylinder cavity 26 so as to form an airtight seal with a sealing member 28 a therebetween. A piston chamber 29 is defined between the lower stopper 27 and the upper stopper 28. An open-close piston 30 is housed in the piston chamber 29 in a manner so as to be slidable with a piston gasket 30 a therebetween.

A lower end portion of an open-close rod 31 in the form of a cylindrical column extending along the first axis L1 is integrally joined to a midsection of an upper surface of the open-close piston 30. The open-close rod 31 slidably extends through the upper stopper 28 so as to form an airtight seal with a sealing member 31 a therebetween, and an upper end of the open-close rod 31 protrudes into a lever reception portion 32 formed in an upper portion of the body 23. A support wall 31 b that is plate-like in shape and supports the pair of open-close levers 25 is formed on the upper end of the open-close rod 31.

A member illustrated in FIG. 4 and denoted by 33 is a ring-shaped permanent magnet attached to the open-close piston 30 and is an object that is to be detected during position sensing. As illustrated in FIGS. 1 and 2, a sensor mounting groove 34 in which a magnetic sensor (not illustrated) is to be received is formed on a front surface and a back surface of the body 23. The magnetic sensor received in the sensor mounting groove 34 senses the permanent magnet 33 to locate the open-close piston 30 in action. Two magnetic sensors may be received in the sensor mounting groove 34 so that both an ascent end and a descent end of the open-close piston 30 are sensed.

Referring back to FIGS. 4 and 5, the piston chamber 29 is partitioned into a first pressure chamber 35 between the open-close piston 30 and the upper stopper 28 and a second pressure chamber 36 between the open-close piston 30 and the lower stopper 27. The first pressure chamber 35 communicates with a first port 37 (see FIG. 1) in the front surface of the body 23 through a channel (not illustrated) extending through the body 23, and the second pressure chamber 36 communicates with a second port 38 (see FIG. 2) in the back surface of the body 23 through an air hole (not illustrated) extending through the body 23.

Thus, a transition from the state in FIG. 4 is made in the following manner: when compressed air is sent into the first pressure chamber 35 through the first port 37 and the second pressure chamber 36 becomes open to the atmosphere through the second port 38, the open-close piston 30 and the open-close rod 31 descend as illustrated in FIG. 6. A transition from the state in FIG. 6, in which the open-close piston 30 and the open-close rod 31 have descended, is made in the following manner: when compressed air is sent into the second pressure chamber 36 through the second port 38 and the first pressure chamber 35 becomes open to the atmosphere through the first port 37, the open-close piston 30 and the open-close rod 31 ascend as illustrated in FIG. 4.

Each of the open-close levers 25 is an L-shaped member including: a first arm 25 a extending on the rod side; and a second arm 25 b extending on the finger 5 side. The two open-close levers 25 are disposed in the lever reception portion 32 at the upper end of the body 23 in a manner so as to face each other in right-and-left directions with the first axis L1 extending therebetween. A portion between the first arm 25 a and the second arm 25 b of the open-close lever 25 is rotatably supported in the body 23 by a lever shaft 39 extending in front-and-back directions of the body 23.

A cutout 25 c that is U-shaped is formed in a tip of the first arm 25 a of the open-close lever 25. An operation pin 40 fixed to the support wall 31 b on the upper end of the open-close rod 31 is engaged in the cutout 25 c. The support wall 31 b is a wall that is plate-like in shape. The operation pin 40 disposed parallel to the lever shafts 39 is attached to the support wall 31 b in such a manner that one end and the other end of the operation pin 40 respectively protrude through a front surface and a back surface of the support wall 31 b. On the front surface side of the support wall 31 b, the operation pin 40 is engaged in the cutout 25 c of one of the open-close levers 25. On the back surface side of the support wall 31 b, the operation pin 40 is engaged in the cutout 25 c of the other open-close lever 25.

An engagement cam 25 d whose outer surface is an arc-shaped cam surface is formed at the tip of the second arm 25 b of the open-close lever 25. The engagement cam 25 d fits into an engagement recess 5 c in the lower surface of the base portion 5 a of the finger 5 through a cavity in the support rail 10 in a manner so as to be swingable in and detachable from the engagement recess 5 c.

Owing to the open-close levers 25 configured as described above, a transition from the state in FIG. 4 is made in the following manner: when the open-close piston 30 and the open-close rod 31 of the cylinder device 24 descend, the tips of the first arms 25 a of the pair of open-close levers 25 are pulled by the operation pin 40 such that the pair of open-close levers 25 rotates so as to cause the engagement cams 25 d at the tips of the respective second arms 25 b to move closer to each other, and consequently, the pair of fingers 5 is closed as illustrated in FIG. 6.

A transition from the state in FIG. 6, in which the pair of fingers 5 is closed, is made in the following manner: when the open-close piston 30 and the open-close rod 31 ascend, the pair of open-close levers 25 rotates so as to cause the engagement cams 25 d at the tips of the respective second arms 25 b to move away from each other, and consequently, the pair of fingers 5 is opened as illustrated in FIG. 4.

Through the opening or closing action of the fingers 5, a workpiece is pinched between the fingers 5 or the pinched workpiece is released.

The linking mechanism 4 is a mechanism by which the finger support part 2 is linked to the chuck main body part 3 via the lock shafts 13. Two linking mechanisms 4 corresponding to the individual lock shafts of the pair of lock shafts 13 are symmetrically placed right and left in a manner so as to face each other in right-and-left directions with the operation mechanism 6 of the body 23 being disposed therebetween. The lock shafts 13 are thus regarded as part of the linking mechanism 4 and may also be referred to as linking shafts.

The linking mechanisms 4, one of which is illustrated in detail in FIG. 5, each include: the lock shaft 13; a shaft insertion hole 44 that is circular and receives the lock shaft 13 inserted therein; a shaft catch mechanism 45 that causes the lock shaft 13 to shift to the non-lock position and catches the lock shaft 13 in the chuck main body part 3 when the lock shaft 13 is inserted into the shaft insertion hole 44; a delinking mechanism 46 that delinks the finger support part 2 from the chuck main body part 3; and a catch-body hold mechanism 56 that holds the catch bodies 19 in the non-catch position after the finger support part 2 is detached.

For formation of the shaft insertion hole 44, a through-hole 47 that is circular and extends along a second axis L2 parallel to the first axis L1 is formed in the body 23. A sleeve 48 in the form of a cylindrical column whose diameter is smaller than the diameter of the through-hole 47 is inserted and placed in a position close to an upper end of the through-hole 47, and the shaft insertion hole 44 is formed on the inside of the sleeve 48.

The sleeve 48 includes, at an upper end thereof, a flange portion 48 a for fixation and is fixed within the through-hole 47 in such a manner that the flange portion 48 a is caught on an upper surface of the body 23 and sandwiched between the body 23 and a plate 49 fixed to the upper surface of the body 23. A taper is provided in such a manner that the inside diameter of an inlet portion of the shaft insertion hole 44 gradually increases toward the inlet, that is, toward the upper end of the sleeve 48.

The sleeve 48 has a plurality of catch-body reception holes 50 facing a hole wall of the shaft insertion hole 44. Each of the catch bodies 19 that are spherical in shape is received in the corresponding one of the catch-body reception holes 50 in a manner so as to be capable of shifting between a catch position where the catch body 19 partially protrudes into the shaft insertion hole 44 and the non-catch position where the catch body 19 does not protrude into the shaft insertion hole 44.

In the example illustrated in the drawings, three catch-body reception holes 50 and three catch bodies 19 received in the respective catch-body reception holes 50 are arranged at 120° intervals about the second axis L2. The number of the catch bodies 19 and the number of catch-body reception holes 50 are each not limited to three and may be, for example, one, two, four, or more than four.

A press member 53 having a cylindrical shape is disposed between an external circumferential surface of the sleeve 48 and an internal circumferential surface of the through-hole 47 in a manner so as to be capable of shifting along the sleeve 48 in the direction of the second axis L2. The press member 53 includes a small-diameter portion 53 a on a proximal end (upper end) side and a large-diameter portion 53 b on a tip (lower end) side. An internal circumferential surface of the small-diameter portion 53 a is slidably in contact with the external circumferential surface of the sleeve 48, and an external circumferential surface of the large-diameter portion 53 b is slidably in contact with the internal circumferential surface of the through-hole 47. The diameter of the large-diameter portion 53 b is greater than the diameter of the small-diameter portion 53 a.

A taper surface 53 c is formed as an inner surface of the press member 53 between the small-diameter portion 53 a and the large-diameter portion 53 b so as to press the catch bodies 19 toward the catch position. The taper surface 53 c slopes toward the tip side of the press member 53 in a manner so as to gradually increase its distance from the second axis L2. When the press member 53 advances toward a press position in a lower place, the taper surface 53 c pushes the catch bodies 19 toward the catch position for protrusion into the shaft insertion hole 44. When the press member 53 retreats to a non-press position in an upper place, the taper surface 53 c releases the catch bodies 19 from the pressed state to allow a shift to the non-catch position.

A press spring 54 surrounding an external circumferential surface of the small-diameter portion 53 a is interposed between the large-diameter portion 53 b of the press member 53 and a spring washer 23 a on the body 23 in a manner so as to be in a compressive state. The press spring 54 exerts energizing force on the press member 53 all the time in an advancement direction in which the catch bodies 19 are pushed to the catch position.

The catch surface 18 a of the lock shaft 13, the catch bodies 19, the press member 53, and the press spring 54 constitute the shaft catch mechanism 45 configured to catch the lock shaft 13 in the chuck main body part 3.

The delinking mechanism 46 includes a release piston 60 driven by air. The release piston 60 is disposed in the through-hole 47 in a manner so as to be slidable in the direction of the second axis L2 with a sealing member 60 a therebetween. The release piston 60 is disposed below the sleeve 48 and the press member 53. An upper end of the release piston 60 is in contact with a lower end of the press member 53.

A release pressure chamber 62 is formed between the release piston 60 and a lower wall 61 that blocks a lower end portion of the through-hole 47 so as to form an airtight seal with a sealing member 61 a therebetween. Through an air hole (not illustrated) formed in the body 23, the release pressure chamber 62 communicates with a release port 63 (see FIG. 1) that is an opening in the front surface of the body 23. When compressed air is sent into the release pressure chamber 62 through the release port 63, the release piston 60 shifts from a descent position illustrated in FIG. 4 to an ascent position illustrated in FIG. 7 and pushes up the press member 53 against the press spring 54.

The release port 63 is the only one release port provided in the front surface of the body 23 and is shared by the individual delinking mechanisms 46 of the two linking mechanisms 4.

The catch-body hold mechanism 56 includes: a hold piston 64 that is disposed in the release pressure chamber 62 in a manner so as to be capable of shifting along the second axis L2; and a hold rod 65 extending upward along the second axis L2 from the hold piston 64. The hold rod 65 extends through a midsection of the release piston 60 in a manner so as to be slidable with a sealing member 65 a therebetween. A tip (upper end) of the hold rod 65 slots into the shaft insertion hole 44 so as to come close to or into contact with the lower end of the lock shaft 13.

An air gap g through which air can flow is provided between an outer circumference of the hold piston 64 and an inner circumference of the release pressure chamber 62. When compressed air is sent into the release pressure chamber 62, air pressure is exerted on an upper surface 64 a and a lower surface 64 b of the hold piston 64, and air pressure force based on the difference between the pressure-receiving area of the upper surface 64 a and the pressure-receiving area of the lower surface 64 b is exerted upward on the hold piston 64.

A hold spring 66 is interposed between a recess 64 c on the lower surface of the hold piston 64 and a recess 61 b on an upper surface of the lower wall 61 in a manner so as to be in a compressed state. The hold spring 66 exerts energizing force upward on the hold piston 64 and the hold rod 65 all the time.

When compressed air is sent into the release pressure chamber 62, the hold piston 64 is thus moved upward by a synthesis of the air pressure force and the energizing force exerted by the hold spring 66.

Each of the delinking mechanisms 46 and each of the catch-body hold mechanisms 56 act in the following manner. When compressed air is sent into the release pressure chamber 62 through the release port 63 in the state in which the finger support part 2 is linked to the chuck main body part 3 as illustrated in FIGS. 4 and 5, the release piston 60 ascends and pushes up the press member 53 against the press spring 54 such that the press member 53 ascends (retreats) to the non-press position illustrated in FIG. 7. Consequently, the catch bodies 19 are released from the pressing force exerted by the press member 53 and become capable of shifting toward the non-catch position, and the finger support part 2 is delinked from the chuck main body part 3. The finger support part 2 may be lifted such that the finger support part 2 makes a transition to the state illustrated in FIG. 7 and is consequently detached from the chuck main body part 3 as illustrated in FIG. 3.

When the finger support part 2 is detached and the lock shaft 13 is pulled out of the shaft insertion hole 44, each of the catch bodies 19 is pushed sideways to the non-catch position in FIG. 7 by the catch surface 18 a that is a circular conical surface of the lock shaft 13.

The hold rod 65 is pushed upward by upward force exerted on the hold piston 64, that is, by a synthesis of the air pressure force and the energizing force exerted by the hold spring 66, and consequently, ascends along with the lock shaft 13 to an ascent end at which the hold piston 64 comes into contact with the release piston 60 as illustrated in FIG. 7. In this state, the hold rod 65 ascends through the shaft insertion hole 44 such that the tip (upper end) thereof reaches a position above the catch bodies 19. Consequently, a side surface of the hold rod 65 comes into contact with the catch bodies 19 caused to shift to the non-catch position and holds the catch bodies 19 in the non-catch position. The press member 53 is caught on the catch bodies 19 so as to remain in the non-press position and still remains in the non-press position after the compressed air in the release pressure chamber 62 is discharged. The release piston 60 also remains at the ascent end.

The strength of the upward force exerted on the hold piston 64, that is, the strength of the synthesis of the air pressure force and the energizing force exerted by the hold spring 66 may be set to be high enough to push up the lock shaft 13 to the position illustrated in FIG. 7 when the release piston 60 causes the press member 53 to shift to the non-press position so as to release the catch bodies 19 from the pressing force.

When the catch bodies 19 shift to the non-catch position as illustrated in FIG. 7, the lock shafts 13 are pushed by the respective lock springs 15 to the lock position, and the pair of fingers 5 is locked; that is, the pair of fingers 5 is rendered incapable of being opened and closed.

After being detached, the finger support part 2 may be linked to the chuck main body part 3 in the following manner: with the release pressure chamber 62 being open to the atmosphere, the lock shafts 13 are inserted into the respective shaft insertion holes 44 such that the lock shafts 13 push down the respective hold rods 65 as illustrated in FIG. 7. As illustrated in FIGS. 4 and 5, each of the lock shafts 13 is then pushed down such that the support rail 10 of the finger support part 2 comes into contact with an upper surface of the plate 49 of the chuck main body part 3 and the catch recess 18 of the lock shaft 13 is placed right next to the catch bodies 19. The press member 53 is then pressed by the press spring 54 to descend (advance) to the catch position where the taper surface 53 c causes the catch bodies 19 to fit into the catch recess 18. Consequently, the catch bodies 19 become caught on the catch surface 18 a, and the finger support part 2 is linked to the chuck main body part 3 accordingly. At the same time, the catch bodies 19 push the catch surface 18 a that is a circular conical surface, and as a result, the lock shaft 13 is pushed down to the non-lock position. Consequently, the pair of fingers 5 is rendered capable of being opened and closed. In this state, the release piston 60 is also pushed down by the press member 53 to the descent position illustrated in FIGS. 4 and 5.

FIGS. 8 to 10 illustrate a second embodiment of the air chuck according to the present invention. An air chuck 1B in the second embodiment differs from the air chuck 1A in the first embodiment in that the delinking mechanisms 46 include manual operation members 70 in place of the release pistons 60 included the air chuck 1A and driven by air pressure. In the air chuck 1B, an upper wall 68 that is a replacement for the release piston 60 is fixedly disposed in the through-hole 47, and a hold chamber 71 between the upper wall 68 and the lower wall 61 is not a pressure chamber and is open to the atmosphere through an air hole (not illustrated) formed in the body 23. Thus, the body 23 does not have a port through which compressed air is sent into the hold chamber 71.

The air chuck 1B is otherwise substantially identical to the air chuck 1A in the first embodiment. The delinking mechanism 46, which is a point of difference, will be described below. Principal constituents identical to those of the air chuck 1A are denoted by the respective reference signs of the corresponding constituents of the air chuck 1A, and description thereof will be omitted.

The delinking mechanism 46 includes the manual operation member 70 in the form of a cylindrical column. The manual operation member 70 is fitted in a mounting hole 72, which is a circular through-hole extending from the front surface to the back surface of the body 23 of the chuck main body part 3, in a manner so as to be rotatable in both forward and reverse directions about an axis orthogonal to the second axis L2. A front end surface and a back end surface of the manual operation member 70 each have a hexagonal operation hole (not illustrated) into which a tool such as a hex wrench may be inserted so as to enable a rotational operation. Such a rotational operation may thus be performed on the manual operation member 70 from either the front surface or the back surface of the body 23.

With external threads being provided on part or the entirety of an outer circumference of the manual operation member 70 and internal threads being provided on part or the entirety of the mounting hole 72, the manual operation member 70 is screw-fitted in the mounting hole 72 and advances or retreats in accordance with the rotational operation performed thereon. Alternatively, the manual operation member 70 and the mounting hole 72 may have no thread so that the manual operation member 70 does not advance or retreat in accordance with the rotational operation performed thereon.

The mounting place for the manual operation member 70 crosses the press member 53 at or around the tip of the press member 53. An operation cam 73 for pushing up the tip of the press member 53 is formed on a portion of the manual operation member 70 that comes close to the tip of the press member 53.

The operation cam 73 is a substantially L-shaped cutout formed by cutting part of a side surface of a cylindrical column and includes a relief portion 73 a and a contact portion 73 b. When the manual operation member 70 is rotated and put into a non-operation position as illustrated in FIG. 8, a lower end portion of the press member 53 is located in the relief portion 73 a and is not pressed by the contact portion 73 b. The energizing force exerted by the press spring 54 causes the press member 53 to advance (descend) to the press position for pressing the catch bodies 19 into the catch position, and the finger support part 2 is linked to the chuck main body part 3 accordingly.

When the manual operation member 70 is rotated to make a transition from this state to the state of being placed in an operation position, the contact portion 73 b of the operation cam 73 comes into contact with a lower end surface of the press member 53 and pushes up the press member 53, as illustrated in FIG. 9. Consequently, the press member 53 retreats (ascends) in a manner so as to compress the press spring 54 and moves into the non-press position for releasing the catch bodies 19 from the pressing force. In this state, the finger support part 2 may be lifted to cause each of the lock shafts 13 to ascend such that the catch bodies 19 are pushed by the catch surface 18 a of the lock shaft 13 to the non-catch position denoted by a dash-dot line in FIG. 9 and make a transition to the state illustrated in FIG. 10. Consequently, the finger support part 2 is completely detached from the chuck main body part 3.

In this state, the hold rod 65 of each of the catch-body hold mechanisms 56 is pushed upward by the hold spring 66 so as to ascend along with the lock shaft 13 and stops at an ascend end at which the hold piston 64 comes into contact with the upper wall 68 as illustrated in FIG. 10. The hold rod 65 comes into contact with the catch bodies 19 caused to shift to the non-catch position and holds the catch bodies 19 in the non-catch position.

The strength of the energizing force exerted by the hold spring 66 may be set to be high enough to push up the lock shaft 13 to the position illustrated in FIG. 10 when the manual operation member 70 causes the press member 53 to shift to the non-press position so as to release the catch bodies 19 from the pressing force.

After being detached, the finger support part 2 may be linked to the chuck main body part 3 in the following manner: as illustrated in FIG. 10, the lock shafts 13 are inserted into the respective shaft insertion holes 44 such that the lock shafts 13 push down the respective hold rods 65 of the catch-body hold mechanisms 56, and each of the lock shafts 13 is pushed down to the position illustrated in FIG. 9. In this state, the catch bodies 19 are placed in the position denoted by the dash-dot line in FIG. 9. The manual operation member 70 is then rotated and placed back into the non-operation position illustrated in FIG. 8, and the press member 53 is pushed by the press spring 54 and descends (advances). Consequently, the catch bodies 19 are pushed by the taper surface 53 c of the press member 53 to come into contact with the catch surface 18 a of the catch recess 18 and push down the lock shaft 13 to the non-lock position, and the finger support part 2 is linked to the chuck main body part 3 via the lock shafts 13 accordingly.

A mark of some kind may be put on each of the manual operation member 70 and the body 23 to enable visual checking of whether the manual operation member 70 is placed in the operation position or the non-operation position.

FIGS. 11 and 12 illustrate a third embodiment of the air chuck according to the present invention. An air chuck 1C in the third embodiment differs from the air chuck 1B in the second embodiment in that the delinking mechanisms 46 include manual operation members 80 that are each in the form of a push button and respectively are provided in a left side surface and a right side surface of the body 23. The configuration is otherwise substantially identical to the configuration of the air chuck 1B in the second embodiment.

In the air chuck 1C in the third embodiment, the left side surface and the right side surface of the body 23 each have a button mounting hole 82 in a position corresponding to the tip of the press member 53, and the manual operation member 80 is supported by a mounting plate 83 and is fitted in the button mounting hole 82 in a manner so as to be capable of advancing toward and retreating away from the press member 53 in the right-and-left directions of the body 23.

The manual operation member 80 is in the form of a rectangular block and has, at a tip thereof, a cam surface 80 a that slopes in a slanting upward direction, in other words, a cam surface 80 a that slopes from a lower surface side toward an upper surface side of the manual operation member 80 in a manner so as to gradually increase its distance from the second axis L2.

The manual operation member 80 is capable of shifting between a non-operation position where the manual operation member 80 protrudes from the body 23 and an operation position where the manual operation member 80 is pushed in the body 23. The manual operation member 80 is configured to hold itself in the operation position with a press from the non-operation position to the operation position and is configured to return back to the non-operation position with the next press.

FIG. 11 illustrates a state in which the finger support part 2 is linked to the chuck main body part 3. In this state, the manual operation member 80 is in full retreat in the non-operation position.

When the manual operation member 80 in this state is pushed into the operation position, the cam surface 80 a of the manual operation member 80 pushes up the lower end of the press member 53 as illustrated in FIG. 12. Consequently, the press member 53 ascends to the non-press position for releasing the catch bodies 19 from the pressing force. Then, the finger support part 2 may be lifted such that the catch surface 18 a of the lock shaft 13 pushes the catch bodies 19 into the non-catch position. Consequently, the individual lock shafts 13 are no longer caught in the chuck main body part 3, and the finger support part 2 is completely detached from the chuck main body part 3.

After being detached, the finger support part 2 may be linked to the chuck main body part 3 in the following manner: the lock shafts 13 are inserted into the respective shaft insertion holes 44 such that each lock shaft 13 pushes down the hold rod 65 of the corresponding catch-body hold mechanism 56 and each lock shaft 13 is pushed into the position illustrated in FIG. 11. The manual operation member 80 is then placed back into the non-operation position, and the press member 53 is pushed by the press spring 54 and descends (advances). Consequently, the catch bodies 19 are pushed by the taper surface 53 c of the press member 53 to come into contact with the catch surface 18 a of the catch recess 18 and push down the lock shaft 13 to the non-lock position, and the finger support part 2 is linked to the chuck main body part 3 via the individual lock shafts 13 accordingly.

REFERENCE SIGNS LIST

-   -   1A, 1B, 1C air chuck     -   2 finger support part     -   3 chuck main body part     -   4 linking mechanism     -   5 finger     -   6 operation mechanism     -   13 lock shaft     -   15 lock spring     -   18 a catch surface     -   19 catch body     -   23 body     -   44 shaft insertion hole     -   45 shaft catch mechanism     -   46 delinking mechanism     -   50 catch-body reception hole     -   53 press member     -   53 c taper surface     -   54 press spring     -   56 catch-body hold mechanism     -   60 release piston     -   65 hold rod     -   66 hold spring     -   70, 80 manual operation member 

1. An air chuck comprising: a finger support part including a pair of fingers that is openable and closable; a chuck main body part including an operation mechanism operable to open and close the pair of fingers; and linking mechanisms that detachably link the finger support part to the chuck main body part, wherein the finger support part includes a pair of lock shafts that shifts between a lock position and a non-lock position, the pair of lock shafts shifts to the non-lock position so as to render the pair of fingers capable of being opened and closed when the finger support part is linked to the chuck main body part, and the pair of lock shafts shifts to the lock position and locks the pair of fingers so as to render the pair of fingers incapable of being opened and closed when the finger support part is detached from the chuck main body part, and each lock shaft of the pair of lock shafts is provided with a corresponding one of the two respective linking mechanisms, and when the finger support part is linked to the chuck main body part, each of the linking mechanisms causes the corresponding lock shaft to shift from the lock position to the non-lock position and links the finger support part to the chuck main body part via the lock shaft.
 2. The air chuck according to claim 1, wherein the pair of lock shafts is capable of shifting between the lock position where the pair of lock shafts is caught in the pair of fingers and the non-lock position where the pair of lock shafts is not caught in the pair of fingers, and each lock shaft is subjected to energizing force exerted by a lock spring toward the lock position, and the linking mechanisms each include: a shaft insertion hole formed in a body of the chuck main body part for insertion of the lock shaft; and a shaft catch mechanism that causes the lock shaft to shift to the non-lock position and catches the lock shaft in the body when the lock shaft is inserted into the shaft insertion hole.
 3. The air chuck according to claim 2, wherein the shaft catch mechanism includes: a catch surface formed on the lock shaft; at least one catch body received in a catch-body reception hole formed in a hole wall of the shaft insertion hole in a manner so as to be capable of shifting between a catch position where the catch body is caught on the catch surface of the lock shaft and a non-catch position where the catch body is off the catch surface; a press member capable of shifting between a press position where the press member presses the catch body toward the catch position and a non-press position where the press member does not press the catch body; and a press spring that exerts energizing force on the press member toward the press position, and the catch surface of the lock shaft is a sloping surface that slopes at an angle from an axis of the lock shaft, and the catch surface causes the lock shaft to shift to the non-lock position when the catch body becomes caught on the catch surface.
 4. The air chuck according to claim 3, wherein the catch body is a sphere, and the press member is cylindrical and is disposed around the shaft insertion hole and the catch body in a manner so as to be capable of advancing and retreating in a direction of an axis of the shaft insertion hole, a taper surface is formed as an inner surface of the press member, the taper surface presses the catch body toward the catch position when the press member advances to the press position, and the taper surface releases the catch body from pressing force when the press member retreats to the non-press position.
 5. The air chuck according to claim 1, wherein the linking mechanisms each include a delinking mechanism that delinks the finger support part from the chuck main body part.
 6. The air chuck according to claim 3, wherein the delinking mechanism includes a release piston driven by air, and the release piston causes the press member to shift to the non-press position when the finger support part is delinked from the chuck main body part.
 7. The air chuck according to claim 3, wherein the delinking mechanism includes a manual operation member, and the manual operation member causes the press member to shift to the non-press position when the finger support part is delinked from the chuck main body part.
 8. The air chuck according to claim 3, wherein the linking mechanisms each include a catch-body hold mechanism that holds, in the non-catch position, the catch body caused to shift to the non-catch position when the finger support part is detached from the chuck main body part.
 9. The air chuck according to claim 8, wherein the catch-body hold mechanism includes a hold rod that slots into the shaft insertion hole in a manner so as to be capable of shifting therein, and when the finger support part is detached from the chuck main body part, the hold rod under action of compressed air or under action of force exerted by a hold spring shifts within the shaft insertion hole along with the lock shaft pulled out of the shaft insertion hole and comes into contact with the catch body in the non-catch position so as to hold the catch body in the non-catch position. 